Set illumination for scenes and maps

Maps and scenes can use illumination to achieve different effects. Maps use illumination mainly to make maps look more three-dimensional—for example, by applying shaded relief or hillshades—but every scene needs a light source to illuminate it. You can configure this light source to achieve different effects within the scene. For 3D faces, such as multipatches or extruded polygons, sun lighting applies shading to the surfaces of the 3D shape. In addition, you can apply atmospheric effects, which allow you to simulate real-world lighting. For example, if you want to show sunset in your scene, you can use atmospheric effects to have a realistic ambience. Use ambient occlusion to make 3D content without textures appear more realistic with depth perception. Use eye-dome lighting to improve the depth perception for point clouds in your scene. You can choose to show stars beyond the globe as well as an atmospheric halo. Depending on whether you are working in a global or local scene, you have different options to define illumination.

An example of a global scene with no atmospheric effects.	An example of a global scene with atmospheric effects.

An example of a global scene with no eye-dome lighting.	An example of a global scene with eye-dome lighting.

An example of a global scene with no ambient occlusion.	An example of a global scene with ambient occlusion.

An example of a global scene with no stars and halo.	An example of a global scene with stars and halo.

Illuminate a global scene

In a global scene, you can set the location of the sun, thereby using light and shading to add more realism to the time of day being displayed. You can choose to show stars beyond the globe as well as an atmospheric halo.

1. In the Contents pane, right-click a map, and click Properties to open the Map Properties dialog box.
2. Click the Illumination tab.
3. Check the Show atmospheric effects check box to simulate a specific mood, such as sunset.
4. Check the Show stars and halo check box to show stars beyond the edge of the globe and an atmospheric halo around the globe.
5. Check the Display shadows in 3D check box to simulate shadows in the scene. Depending on the light source, 3D features such as multipatches or extruded polygons can have shadows. Keep in mind that simulating shadows can impact drawing performance.
6. Check the Use ambient occlusion check box to make 3D content without textures appear more realistic with depth perception. If you add a layer with textures you may want to turn off ambient occlusion because the textures already have lighting information included. Ambient occlusion can impact drawing performance. This option is checked on by default.
7. Check the Use eye-dome lighting check box to apply eye-dome lighting effects to the scene. Eye-dome lighting improves depth perception for LAS datasets and point cloud scene layers. This option is checked on by default. If this option is turned off, eye-dome lighting is disabled for all layers, regardless of the eye-dome lighting setting of each layer.
8. Set Light contribution to define the brightness of the scene. Light contribution is not available if Show atmospheric effects is checked. In that case, the light is simulated depending on the position of the sun.
9. Choose how to define the sun position for the scene:
   • By specifying Noon at camera position, where ambient light is equal regardless of where on the globe the camera is positioned.
   • By Date and time, including the time zone.
   • By the Absolute sun position, specified by latitude and longitude.
   • By the Map time, which is only available if a map time is set for the scene.

Illuminate a local scene

In local scenes, only spot lighting is available. You can set the azimuth and altitude of the light source, as well as the amount of contrast, used in rendering the illumination of the scene. The illumination properties for a scene apply shading to all areal features, including 3D faces and surface data.

1. In the Contents pane, right-click a map, and click Properties to open the Map Properties dialog box.
2. Click the Illumination tab.
3. Turn on Shadows options.
   • Check the Display shadows in 3D check box to simulate shadows in the scene. Depending on the light source, 3D features such as multipatches or extruded polygons can have shadows. Simulating shadows can impact drawing performance.
   • Check the Use ambient occlusion check box to make 3D content without textures appear more realistic with depth perception. If you add a layer with textures you may want to turn off ambient occlusion because the textures already have lighting information included. Ambient occlusion can impact drawing performance. This option is checked on by default.
   • Check the Use eye-dome lighting check box to apply eye-dome lighting effects to the scene. This will improve the depth perception for LAS datasets and point cloud scene layers. This option is checked on by default. If this option is turned off, all layers will have eye-dome lighting disabled, regardless of the eye-dome lighting setting which are set from the layer's Appearance tab on the ribbon.
4. Adjust the azimuth angle.

   The azimuth is the angular direction of the sun, measured from north in clockwise degrees from 0 to 360. An azimuth of 90º is east. The default azimuth is 315º (NW). Default sun azimuth (direction) for hillshade is 315º.

5. Adjust the altitude.

   The altitude is the slope or angle of the illumination source above the horizon. The units are in degrees, from 0 (on the horizon) to 90 (overhead). The default is 90 degrees. Default sun altitude for hillshade is 45º.

6. Adjust the contrast.

   The contrast controls the amount of shading applied to a surface. No contrast is 100 on the contrast scale, and 0 is the highest contrast.

Illuminate a 2D map

You may want to change the illumination angle when applying a shaded relief or hillshade to a digital elevation model (DEM).

1. In the Contents pane, right-click a map, and click Properties to open the Map Properties dialog box.
2. Click the Illumination tab.
3. Adjust the azimuth angle.
4. Adjust the altitude angle.
5. Optionally, you can adjust the contrast of the hillshading.
6. Click Restore Default to reset your changes to the default illumination values.